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A middle-aged woman with microscopic hematuria detected at a medical check-up

      Keywords

      1. Case description

      A 56-year-old woman presented to the author's hospital with microscopic hematuria detected at a medical check-up. Vital signs were normal, and the patient had no symptoms. Laboratory evaluation showed that hemoglobin and serum creatinine levels were 12.1 g/dL and 0.74 mg/dL, respectively. Urine cytology confirmed no evidence of malignancy. Ultrasonography (USG) revealed compression of the left renal vein between the aorta and the superior mesenteric artery, with impaired blood outflow accompanied by distention of the distal portion of the vein (Fig. 1). What is the diagnosis?
      Fig. 1
      Fig. 1Ultrasonography revealing entrapment of the left renal vein (LRV) between the abdominal aorta (Ao) and superior mesenteric artery (SMA).

      2. Discussion section

      This finding is known as nutcracker phenomenon (NCP). Spontaneous resolution of microhematuria was obtained by conservative approach. The first clinical report of NCP was by El-Sadr and Mina [
      • El-Sadr A.R.
      • Mina E.
      Anatomical and surgical aspects in the operative management of varicocele.
      ] in 1950. The exact prevalence of NCP is unknown, and why NCP occurs in adults is less clear [
      • Kurklinsky A.K.
      • Rooke T.W.
      Nutcracker phenomenon and nutcracker syndrome.
      ]. However, a decrease in retroperitoneal fat is believed to reduce the aortomesenteric angle; thus, lower body mass index (BMI) correlates positively with NCP [
      • Ozkurt H.
      • Cenker M.M.
      • Bas N.
      • Erturk S.M.
      • Basak M.
      Measurement of the distance and angle between the aorta and superior mesenteric artery: normal values in different BMI categories.
      ]. In fact, the patient's BMI was 20.0 (height: 166.3 cm, weight: 55.4 kg).
      Several imaging methods, including USG, computed tomography angiography, magnetic resonance angiography and retrograde venography, have been used to diagnose NCP. Especially, USG is useful for the noninvasive diagnosis of NCP; Doppler USG has a sensitivity of 78% and a specificity of 100% [
      • Takebayashi S.
      • Ueki T.
      • Ikeda N.
      • Fujikawa A.
      Diagnosis of the nutcracker syndrome with color Doppler sonography: correlation with flow patterns on retrograde left renal venography.
      ].
      The term nutcracker syndrome should be reserved for patients with characteristic clinical symptoms associated with demonstrable nutcracker morphologic features [
      • Kurklinsky A.K.
      • Rooke T.W.
      Nutcracker phenomenon and nutcracker syndrome.
      ], such as hematuria and left flank pain. The severity of the syndrome varies from asymptomatic microhematuria to severe pelvic congestion, and hematuria is the most commonly reported symptom. Management options range from observation to nephrectomy, depending on the severity of symptoms; conservative treatment is recommended for mild hematuria [
      • Dever D.P.
      • Ginsburg M.E.
      • Millet D.J.
      • Feinstein M.J.
      • Cockett A.T.
      Nutcracker phenomenon.
      ].

      Conflict of interest

      None declared.

      References

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        Anatomical and surgical aspects in the operative management of varicocele.
        Urol Cutaneous Rev. 1950; 54: 257-262
        • Kurklinsky A.K.
        • Rooke T.W.
        Nutcracker phenomenon and nutcracker syndrome.
        Mayo Clin Proc. 2010; 85: 552-559
        • Ozkurt H.
        • Cenker M.M.
        • Bas N.
        • Erturk S.M.
        • Basak M.
        Measurement of the distance and angle between the aorta and superior mesenteric artery: normal values in different BMI categories.
        Surg Radiol Anat. 2007; 29: 595-599
        • Takebayashi S.
        • Ueki T.
        • Ikeda N.
        • Fujikawa A.
        Diagnosis of the nutcracker syndrome with color Doppler sonography: correlation with flow patterns on retrograde left renal venography.
        Am J Roentgenol. 1999; 172: 39-43
        • Dever D.P.
        • Ginsburg M.E.
        • Millet D.J.
        • Feinstein M.J.
        • Cockett A.T.
        Nutcracker phenomenon.
        Urology. 1986; 27: 540-542